1,2,3,3,4,4,5,5-Octafluorocyclopentene (hereinafter, also referred to as “octafluorocyclopentene”) is useful as a gas for plasma reaction in etching, chemical vapor deposition (CVD), and so forth that may be performed in a manufacturing step of a semiconductor device or as a feedstock for a fluorine-containing pharmaceutical intermediate, a photochromic molecule material, or the like. Highly purified octafluorocyclopentene, in particular, can suitably be used as a plasma etching gas, CVD gas, or the like that can be used in a manufacturing step of a semiconductor device.
A number of methods of manufacturing octafluorocyclopentene have been proposed in recent years. For example, Patent Literature (PTL) 1 discloses that octafluorocyclopentene was obtained in a yield of 93.1% by using potassium fluoride to perform fluorination in N,N-dimethylformamide solvent with respect to a mixture of compounds including at least two chlorine atoms that was obtained through fluorination of hexachlorocyclopentadiene by anhydrous hydrogen fluoride. This mixture contained 1,2-dichlorohexafluorocyclopentene, 1,2,3-trichloroheptafluorocyclopentene, and 1,2,3,5-tetrachlorotetrafluorocyclopentene.
PTL 2 discloses that octafluorocyclopentene was obtained in a yield of 87.8% using 1,2-dichlorohexafluorocyclopentene as a feedstock by carrying out a reaction in N,N-dimethylformamide solvent using potassium fluoride as a fluorinating agent while adjusting the dripping rate of the feedstock and the withdrawal rate of octafluorocyclopentene (product).
PTL 3 discloses that octafluorocyclopentene was obtained in a yield of 90% by using potassium fluoride to perform fluorination of a mixture containing 1-chloroheptafluorocyclopentene, 1,2-di chlorohexafluorocyclopentene, trichloropentafluorocyclopentene, tetrachlorotetrafluorocyclopentene, and pentachlorotrifluorocyclopentene that was obtained through gas phase fluorination by anhydrous hydrogen fluoride using octachlorocyclopentene as a starting material.
PTL 4 discloses that octafluorocyclopentene was obtained in a yield of 87% by using potassium fluoride to fluorinate a feedstock having 1-chloroheptafluorocyclopentene as a main component in N,N-dimethylformamide solvent.
PTL 5 discloses that octafluorocyclopentene was obtained in a yield of 72% using 1-chloroheptafluorocyclopentene as a feedstock by performing heating under reflux in a mixed solvent of N,N-dimethylformamide and benzene, which is a non-polar solvent, with potassium fluoride as a fluorinating agent.
Non-Patent Literature (NPL) 1 discloses that octafluorocyclopentene was obtained in a yield of 72% using octachlorocyclopentene as a feedstock by performing fluorination in N-methylpyrrolidone solvent with potassium fluoride as a fluorinating agent.